Jason Wang
2022-Nov-24 06:34 UTC
[PATCH] vhost_vdpa: fix the crash in unmap a large memory
On Thu, Nov 24, 2022 at 2:23 PM Cindy Lu <lulu at redhat.com> wrote:> > While testing in vIOMMU, sometimes guest will unmap very large memory, > which will cause the crash.Would you mind to post the calltrace?> To fix this,Move the iommu_unmap to > vhost_vdpa_pa_unmap/vhost_vdpa_va_unmap and only unmap the memory > that saved in iotlb. > > Signed-off-by: Cindy Lu <lulu at redhat.com>Let's add a fixes tag which I believe should be the first commit that introduces vhost-vDPA. And let's cc stable as well.> --- > drivers/vhost/vdpa.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c > index 166044642fd5..c392979702cf 100644 > --- a/drivers/vhost/vdpa.c > +++ b/drivers/vhost/vdpa.c > @@ -692,6 +692,8 @@ static void vhost_vdpa_pa_unmap(struct vhost_vdpa *v, > struct vhost_iotlb_map *map; > struct page *page; > unsigned long pfn, pinned; > + struct vdpa_device *vdpa = v->vdpa; > + const struct vdpa_config_ops *ops = vdpa->config; > > while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) { > pinned = PFN_DOWN(map->size); > @@ -703,6 +705,8 @@ static void vhost_vdpa_pa_unmap(struct vhost_vdpa *v, > unpin_user_page(page); > } > atomic64_sub(PFN_DOWN(map->size), &dev->mm->pinned_vm); > + if ((ops->dma_map == NULL) && (ops->set_map == NULL)) > + iommu_unmap(v->domain, map->start, map->size); > vhost_iotlb_map_free(iotlb, map); > } > } > @@ -713,11 +717,15 @@ static void vhost_vdpa_va_unmap(struct vhost_vdpa *v, > { > struct vhost_iotlb_map *map; > struct vdpa_map_file *map_file; > + struct vdpa_device *vdpa = v->vdpa; > + const struct vdpa_config_ops *ops = vdpa->config; > > while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) { > map_file = (struct vdpa_map_file *)map->opaque; > fput(map_file->file); > kfree(map_file); > + if ((ops->dma_map == NULL) && (ops->set_map == NULL)) > + iommu_unmap(v->domain, map->start, map->size);I wonder if it's better to move at least dma_map() here. Thanks> vhost_iotlb_map_free(iotlb, map); > } > } > @@ -805,8 +813,6 @@ static void vhost_vdpa_unmap(struct vhost_vdpa *v, > } else if (ops->set_map) { > if (!v->in_batch) > ops->set_map(vdpa, asid, iotlb); > - } else { > - iommu_unmap(v->domain, iova, size); > } > > /* If we are in the middle of batch processing, delay the free > -- > 2.34.3 >